Fire showing in viewport, not in render
Slightly adjusted nodes to render fire:



You need to add the bottom four nodes. They utilize the Attribute node's flame setting to detect fire. The ColorRamp node determines the color. The top Multiply node determines the smoke's thickness. The bottom Multiply node determines the fire's thickness.

Result produced by these settings (a lightsaber on fire) ( :) ):



This is your .blend file with the above nodes. I would include a screenshot of your final render instead of my stuff, but I do not have the smoke cache.